Emergent Pair Density Waves in Van Hove Metals: The Case Study of Bilayer 1T'-WTe₂

Pair density wave (PDW) superconductivity, where Cooper pairs acquire finite momentum and form a spatially modulated condensate, represents one of the most intriguing yet elusive states of quantum matter. While PDWs have been proposed to emerge in magnetic fields or as secondary orders intertwined with charge or spin density waves, or from spontaneously valley-polarized (quarter-metal) normal states, conclusive evidence for a primary PDW state—arising without any preexisting order, polarization, or field—remains rare.

In this talk, I will propose a new class of materials—rectangular-lattice Van Hove metals—as promising hosts for primary PDWs. Using bilayer 1T’-WTe₂ as a case study, our combined density-functional theory and renormalization-group analysis reveal that electrostatic gating can tune the system to a regime with two perfectly nested Van Hove singularities near the Fermi level. The resulting Van Hove fermiology naturally favors finite-momentum pairing over competing charge or spin density waves. I will conclude by discussing experimental signatures that can test these predictions of an intrinsic PDW phase in bilayer WTe₂.